Cheeki Rafiki After Losing Keel

When the keel on the Cheeki Rafiki, a Beneteau 40.7 sailing yacht, broke off in a storm in the mid-Atlantic in May 2014, the yacht capsized and four UK sailors died. Why did the keel fall off and who was to blame for the deaths?

In response to the second part of the question, the British courts chose to blame Douglas Innes, managing director of the Stormforce Coaching, the firm which owned and was responsible for the maintenance of the yacht. Innes was charged with manslaughter and with failing to operate the yacht in a safe manner. In July of last year, he was found guilty of the lesser charge, failing to operate the yacht in a safe manner, contrary to the Merchant Shipping Act. At the end of last month, a jury acquitted Innes of the manslaughter charges.

Without going into the specifics of the case, it appears that the jury reached a thoughtful and informed decision. Interestingly, after deciding to acquit, the jury sent a note to the judge expressing a concern about the standards for safety in pleasure craft.

While it may be emotionally satisfying to find fault, answering the question “who is to blame?” in this case is not easy. The question, “how did the keel fall off?” is easier to answer, but paradoxically perhaps, makes the question of blame more difficult. It can be difficult to decide what represents an inherent design flaw in the boat, the unforeseen results of an accident, or simple negligence. It is possible for all three factors to play a role.   

In the case of the Cheeki Rafiki, the UK Marine Accidents Investigation Branch (MAIB) found a range of possible structural failures which included “a combined effect of previous groundings and subsequent repairs to its keel and matrix had possibly weakened the vessel’s structure where the keel was attached to the hull. It is also possible that one or more keel bolts had deteriorated. A consequential loss of strength may have allowed movement of the keel, which would have been exacerbated by increased transverse loading through sailing in
worsening sea conditions.”

A keel falling off is a rare but sadly not uncommon event on modern sailboats. Since 1984 there have been at least 74 known cases of lost keels, which involved no fewer than 26 deaths by drowning. The 74 known failures are a tiny percentage of the number of fiberglass boats with fin keels sailing in the world today, nevertheless, they raise serious concerns. It is unknown how may keel failures were responsible for sailboats and their crews which simply disappeared. 

Unfortunately, in modern fin keel fiberglass boats, there is often no one single cause for a keel failure. The keel is usually connected to the hull by keel bolts, which are often supported by a “matrix” or grillage system of stiffeners. The stiffeners are designed to transmit the huge loads from the keel to the hull, while still keeping the hull as light as practicable. All the fine engineering that goes into such a design can literally fall apart with wear and tear on the boat. Even minor groundings can damage the hull structure and begin a process which ends in the failure of the keel. In one analysis of failed keels, fewer than 10% of the known failures were attributed to keel bolts, whereas 25% were related to hull failure, 25% to grounding, and 32% to welded keel failures.

One recent tragedy may be especially telling. The Dutch designer and boatbuilder Frans Maass had a reputation for designing and building strong and safe boats. On July 1, 2017, Capella, a yacht designed by Maass and built for him in his boatyard, capsized after losing her keel during the Genisol Light Vessel Race off Ostend, Belgium. Frans Maas and one other crew died in the capsize.

The problem is that in the case of many modern fin keel sailboats, it is difficult even to identify damage to the hull structure from grounding or simply the load from the keel as it is transferred to the hull. If a well respected and experienced designer like Frans Maass died after his own boat lost its keel, the challenges to regular sailors with production fin keel boats can be indeed daunting.

Thanks to David Rye for contributing to this post.